Bryant II TSTAT-0-16, II TSTAT-0-20 Installation And Start-up Instructions Manual
installation and
start-up instructions
THERMIDISTAT™ CONTROL
TSTAT
Cancels: II TSTAT-0-16 II TSTAT-0-20
5-98
NOTE: Read the entire instruction manual before starting the
installation.
This symbol → indicates a change since the last issue.
INDEX
Page
SAFETY CONSIDERATIONS.....................................................1
INTRODUCTION..........................................................................1
INSTALLATION CONSIDERATIONS.......................................1
INSTALLATION........................................................................1-7
Thermidistat Control Location..............................................1-2
Set DIP Switches......................................................................2
Install Thermidistat Control..................................................2-3
Set Thermidistat Control Configuration ...............................3-6
System Start-Up and Checkout.............................................6-7
Final Settings ............................................................................7
HUMIDITY CONTROL FEATURES.....................................7-10
Humidification.......................................................................7-8
Dehumidification ...................................................................8-9
Vacation...............................................................................9-10
OPERATIONAL INFORMATION........................................10-19
WIRING DIAGRAMS ...........................................................11-19
THERMIDISTAT CONTROL TROUBLESHOOTING............19
SAFETY CONSIDERATIONS
Read and follow manufacturer instructions carefully. Follow all
local electrical codes during installation. All wiring must conform
to local and national electrical codes. Improper wiring or installation may damage Thermidistat Control.
Recognize safety information. This is the safety-alert symbol
When you see this symbol on the equipment and in the instruction
manual, be alert to the potential for personal injury.
Understand the signal words DANGER, WARNING, and CAUTION. These words are used with the safety-alert symbol. DANGER identifies the most serious hazards which will result in severe
personal injury or death. WARNING signifies a hazard which
could result in personal injury or death. CAUTION is used to
identify unsafe practices which would result in minor personal
injury or product and property damage.
INSTALLATION CONSIDERATIONS
A. Power
Note that this control does not require batteries and is not "power
stealing." It does require 24vac (R and C terminals) of the
low-voltage transformer to be connected to it for proper operation.
It will not operate without these 2 connections.
B. Models
There is a single programmable/non-programmable model for all
applications. It can be configured for AC or HP, 1- or 2-speed
compressor, and for dual fuel installations, allowing it to be used
in place of all Bryant thermostats.
C. Humidify Equipment and Connections
The humidify output connects directly to 24vac operated humidifiers. No other connection or interlock is required. Any of several
installer-selectable operating modes are available.
D. Dehumidify Equipment and Connections
The dehumidify output connects to the dehumidify input on
variable-speed furnaces and fan coils. Additional dehumidification
is done by controlling the compressor. A variety of operating
modes are available.
E. Outdoor Temperature Sensor
→
Optimum performance is obtained when an outdoor temperature
sensor is used with the Thermidistat Control. Plan installation so
that 2 wires can be run from Thermidistat Control to an outdoor
location, preferably on the north side of the house or refer to
Installation Instructions included with the outdoor temperature
.
sensor for simplified connection. Sensor can be mounted to
outdoor unit and existing control wires may be used for its
connection. Details are provided in sensor instructions.
®
INTRODUCTION
Bryant’s 7-day programmable Thermidistat Control is a wallmounted, low-voltage control which combines temperature and
humidity control in a single attractive unit. An extension of
Bryant’s proven line of thermostats, it provides separate set points
for heating and cooling, and now adds humidification and dehumidification. Different heating and cooling set points and times are
programmable for 4 periods per day and 7 days per week. The
Thermidistat Control can also be field-configured as a nonprogrammable thermostat. When operating in the nonprogrammable configuration it will still have both temperature and
humidity control. Humidify and dehumidify outputs provide direct
control of humidity. Batteries are not used. During power loss an
internal memory stores programs and settings for unlimited time,
and the clock continues to run for at least 8 hr.
A96373
HEIGHT (IN.) WIDTH (IN.) DEPTH (IN.)
4-1/4 7-1/2 1-3/8
Fig. 1—Thermidistat Control
INSTALLATION
I. THERMIDISTAT CONTROL LOCATION
Thermidistat Control should be mounted:
• Approximately 5 ft (1.5m) from floor.
• Close to or in a frequently used room, preferably on an inside
partitioning wall.
—1—
• On a section of wall without pipes or duct work.
Thermidistat Control should NOT be mounted:
• Closeto a window, on an outside wall, or next to a door leading
to the outside.
• Exposed to direct light and heat from a lamp, sun, fireplace, or
other temperature-radiating object which may cause a false
reading.
• Closeto or in direct airflow from supply registers and return-air
registers.
• In areas with poor air circulation, such as behind a door or in
an alcove.
II. SET DIP SWITCHES
There is a 4 section DIP switch within the Thermidistat Control
which must be properly set by the installer. It is easiest to set these
4 switches before the Thermidistat Control is mounted to the wall,
so STOP and complete the following steps:
1. Open hinged Thermidistat Control cover.
2. Remove cover completely by snapping it apart at hinge.
3. Open Thermidistat Control by pressing back half of the
right end of plastic case inward while, at the same time,
pulling front and back halves apart at the right end. The 2
halves will swing apart.
4. Snap hinge apart to completely separate the 2 halves.
5. Switches are located in upper right corner of circuit board.
To change switch position, use corner of a small screwdriver to slide switch to opposite position.
6. After switches have been set, do not reassemble the 2
halves. The rear plastic will be first mounted to wall.
A. Switch 1—AC/HP Select
Use this switch to select between air conditioner and heat pump
systems.
TO SET:
OFF—for air conditioner installations. This is factory default.
ON—for heat pump installations, using either a fan coil or furnace
(dual fuel).
B. Switch 2—1 Speed/2 Speed
This switch tells the system whether the compressor is 1 or 2
speed.
TO SET:
OFF—for single-speed compressor. This is factory default.
ON—for 2-speed compressors, whether AC or HP.
III. INSTALL THERMIDISTAT CONTROL
WARNING: Before installing Thermidistat Control,
turn off all power to equipment. There may be more than
1 power disconnect. Electrical shock can cause personal
injury or death.
1. Turn off all power to equipment.
2. If an existing thermostat is being replaced:
a. Remove existing thermostat from wall.
b. Disconnect wires from existing thermostat, 1 at a time.
c. As each wire is disconnected, record wire color and
terminal marking.
d. New or additional wire may be needed to accommodate
added humidity outputs.
e. Discard or recycle old thermostat.
NOTE: Mercury is a hazardous waste and MUST be disposed of
properly.
3. Select Thermidistat Control rear plastic. (If it is not separated from the remainder of the Thermidistat Control, refer
to Step 2 above.)
4. Route wires through large hole in rear plastic. Level rear
plastic against wall (for aesthetic value only—Thermidistat
Control need not be leveled for proper operation) and mark
wall through 2 mounting holes.
5. Drill two 3/16-in. mounting holes in wall where marked.
6. Secure rear plastic to wall with 2 screws and anchors
provided. Additional mounting holes are available for more
secure mounting if needed. Make sure all wires extend
through hole in mounting base.
7. Adjust length and routing of each wire to reach proper
connector block and terminal on rear plastic with 1/4-in.
extra length. Strip only 1/4 in. of insulation from each wire
to prevent adjacent wires from shorting together when
connected.
8. Match and connect equipment wires to proper terminals of
each connector block. (See Table 6 and Wiring Diagrams
Fig. 3 through 30.) Remember R and C must be connected
for proper operation.
CAUTION: Improper wiring or installation may damage
Thermidistat Control. Check to make sure wiring is
correct before proceeding with installation or turning on
power.
C. Switch 3—Smart/Conventional Recovery
Selects between conventional and smart recovery from setback.
Conventional recovery changes to new set point at programmed
time. Smart recovery, which is active in both heating and cooling,
starts 90 minutes earlier and smoothly adjusts set point so room
will arrive at programmed temperature at programmed time.
TO SET:
OFF—for smart recovery. This is factory default.
ON—for conventional recovery.
D. Switch 4—Installer Test OFF/ON
Selects a special installer test mode which assists with checkout
and troubleshooting. See Step 5.
TO SET:
OFF—for normal operation. This is factory default.
ON—for installer test mode.
9. Push any excess wire into wall and against rear plastic. Seal
hole in wall to prevent air leaks. Leaks can affect operation.
10. Reattach Thermidistat Control body to rear plastic by first
reattaching hinge.
11. Close Thermidistat Control assembly, making sure pins on
back of circuit board align with sockets in connector.
12. Turn on power to equipment.
On power up, all display segments will light for 5 sec. For the next
5 sec, a 2-digit code appears on large display which identifies
Thermidistat Control configuration:
1. AC—for 1-speed air conditioner
2. HP—for 1-speed heat pump
3. A2—for 2-speed air conditioner
4. H2—for 2-speed heat pump
—2—
5. dF—for 1-speed dual fuel
6. d2—for 2-speed dual fuel
7. HS—for special 3-stage auxiliary heat with FK series Fan
Coil and 1-speed heat pump
When this identifier disappears, normal operation begins. The
MODE control should be set to OFF and FAN control to AUTO,
so equipment does not start until further configuration and checkout is completed.
IV. SET THERMIDISTAT CONTROL CONFIGURATION
Configuration options, like DIP switch settings, are intended to be
selected at installation and normally are not modified by the
homeowner. These options are not discussed in the homeowner’s
manual and therefore must be made as part of the installation. A
special procedure allows entry into the configuration mode. While
in configuration mode, up to 17 selections can be made. A
description of each selection and how to use the configuration
mode follows.
A. Configuration Options — Summary:
Option 1—Anticipator adjustment
Option 2—Clean filter timer adjustment
Option 3—English/Metric selection
Option 4—Fan (G) ON with W selection
Option 5—Variable-speed blower present selection
Option 6—Cooling lockout below 55° selection
Option 7—Variable speed super dehumidification selection (only
available when variable-speed blower is used)
Option 8—Auxiliary heat lockout temperature adjustment (only
available when heat pump is used)
Option 9—Three-stage auxiliary heat selection (only available
when single-speed heat pump is used)
Option 10—Dual fuel selection (only available when heat pump is
used)
Option 11—Dual fuel crossover temperature adjustment (only
available when dual fuel is selected)
Option 12—Defrost heat selection (only available when heat pump
is used)
Option 13—Room temperature offset adjustment
Option 14—Heat/cool dead band adjustment
Option 15—Enable auto mode
Option 16—Reserved for future use
Option 17—Non-Programmable selection
B. To Enter Configuration Mode:
Press and hold FAN button for approximately 10 sec until COOL
set point display indicates a flashing 01. The Thermidistat Control
is now in configuration mode. It will automatically exit this mode
if no button is pressed for 3 minutes. Pressing END button will exit
configuration mode immediately.
C. While in Configuration Mode:
The upper small (COOL set point) display indicates selected
option number and large display indicates selection made within
that option. One of these will be flashing. The up and down buttons
are used both to move between available options and to make
selection for each option. When option number (small display) is
flashing, up and down buttons adjust it, moving between available
option numbers. After desired option number has been selected,
press SET TIME/TEMP button once. The large display will now
flash, indicating that up and down buttons now control available
choices within that option. Each press of TIME/TEMP button
switches between available option (small display) and available
selections within each option (large display).
D. Configuration Options — Selection:
OPTION 1—ANTICIPATOR ADJUSTMENT
This adjustment controls sensitivity and cycle rate of Thermidistat
Control. Higher numbers decrease sensitivity and slow cycle rate.
Lower numbers increase sensitivity and cycle rate. However, a
limiting feature will not allow more than 4 cycles per hr, regardless
of setting. Anticipator values can range from 1 to 9. Factory
default is 3. This default selection provides optimum performance
in nearly all installations. Try it first. Do not change setting unless
there is evidence of need to do so.
Unlike conventional anticipators, this setting is not determined by
current draw. There is no need to measure, know, or compensate
for current draw. There is also no droop with this Thermidistat
Control. Regardless of setting and number of stages, both heating
and cooling will control to their respective set points.
TO ADJUST:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." The upper small (COOL
set point) display will be flashing 01. If not, use up and
down buttons to move it to 01.
2. Press SET TIME/TEMP button once to flash current
selection of 1, 2, 3, 4, 5, 6, 7, 8, or 9 on large display.
Factory default is 3.
3. Use up and down buttons to move between available
choices.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
OPTION 2—CLEAN FILTER TIMER
Select hours of blower operation (heating, cooling, or fan) before
CLEAN FILTER icon is displayed. With OFF selected, icon will
never come on, disabling this feature. Time selection can range
from 400 to 3600 hr by selecting numbers 1 through 9. (Time is
400 X number selected.) Factory default is 2 (800 hr). Recommended selections are: disposable filter—400 to 800 hr, media
filter—1200 to 1600 hr, or electronic air cleaner—1600 to 2400 hr
of blower operation.
TO SELECT OR ADJUST:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 02.
2. Press SET TIME/TEMP button once to display current
selection of OF, 1, 2, 3, 4, 5, 6, 7, 8, or 9 on large display.
Factory default is 2.
3. Use up and down buttons to move between available
choices.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
OPTION 3—ENGLISH/METRIC
Select between Fahrenheit and Celsius operation. Factory default
is Fahrenheit.
TO SELECT OR ADJUST:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 03.
2. Press SET TIME/TEMP button once to flash current
selection of F or C. Factory default is F.
3. Use up and down buttons to move between F and C on large
display.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
—3—
OPTION 4—FAN (G) ON WITH W
This selection determines whether fan (G) output is to be ON or
OFF when any W (furnace or strip heat) output is ON. Most
furnaces and fan coils manage their own blowers and do not
require separate G signal. For these applications, select OFF. Some
auxiliary heaters require separate G signal to turn on blower. In
this case, select ON. Factory default is OF (off).
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 04.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to alternate between OF and ON on
large display.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
OPTION 5—VARIABLE SPEED (ICM) BLOWER
If furnace or fan coil contains a variable-speed (ICM) blower, set
this option to ON. For normal (PSC) blowers, set to OF. This
selection enables system to use special features available only in
units with an ICM blower. Factory default is OF (off).
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 05.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to alternate between OF and ON on
large display. Factory default is OF.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
OPTION 6—COOLING LOCKOUT BELOW 55°F
This option disables cooling when outdoor temperature is below
55°F. It requires an outdoor temperature sensor. Set to OF to allow
cooling below 55°F. Set to ON to prevent cooling below 55°F.
Factory default is OF (off).
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 06.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to alternate between OF and ON on
large display. Factory default is OF.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
OPTION 7—VARIABLE SPEED SUPERDEHUMIDIFY
→
This option requires prior selection of variable-speed (ICM)
blower (Option 5). When selected, this option operates blower at
further reduced airflow from that of normal dehumidification when
there is a dehumidification demand without a cooling demand,
achieving maximum humidity removal with minimum cooling. It
is done by supplying blower with a Y signal and no G signal on a
call for cooling. Not all products with ICM blowers have this
feature. Check Installation Instructions for ICM air handler used.
Select OF for normal operation (Y and G supplied on a cooling
call). Select ON for super dehumidification (Y with no G on a
dehumidify only call). Factory default is OF (off).
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 07.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to alternate between OF and ON on
large display. Factory default is OF.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
OPTION 8—AUXILIARY HEAT LOCKOUT TEMPERATURE
This option requires prior selection of heat pump (DIP switch 1
ON). It allows selection of an outdoor temperature of OF, 5, 10,
15, 20, 25, 30, 35, 40, 45, 50, or 55°F. Outdoor temperature sensor
MUST be attached. If temperature is selected and outdoor temperature sensor is not attached, error message E3 will appear. See
"Error Codes." In heat pump systems, auxiliary heat is prevented
from operating for outdoor temperatures above selected temperature. In dual fuel systems, furnace is prevented from operating for
outdoor temperatures above selected temperature. However, heat
pump or furnace may be used during defrost. See Configuration
Option No. 12. If OF is selected, outdoor temperature does not
affect system operation. Factory default is OF (off).
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 08.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to move between OF, 5, 10, 15, 20,
25, 30, 35, 40, 45, 50, or 55 on large display. Factory
default is OF.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
OPTION 9—SPECIAL 3-STAGE ELECTRIC HEAT
This option requires prior selection of single-speed heat pump
(DIP switch 1—ON, DIP switch 2—OF). It provides 3 stages of
electric heat from W1 and W2 by sequencing W1 only, then W2
only, then both W1 and W2. See FK Series Fan Coil Installation
Instructions for further information. For 3-stage heat, select ON.
For normal 1- or 2-stage heat, select OF. Factory default is OF
(off).
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 09.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to alternate between OF and ON on
large display. Factory default is OF.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
OPTION 10—DUAL FUEL EQUIPMENT
CAUTION: All dual fuel installations must be equipped
with a high pressure switch to turn off compressor under
a high indoor coil pressure condition.
The high pressure switch protects compressor and indoor coil from
→
overpressure which would occur if a failure or wiring error
resulted in the heat pump and furnace operating at the same time.
—4—
High Pressure Switch Kit includes required switch and instructions
for proper operation. For all dual fuel installations, outdoor
temperature sensor must be attached. If not, E3 error message will
appear. See "Error Codes."
This option requires prior selection of heat pump (DIP switch
1—ON), and must be selected in dual fuel installations. It prevents
simultaneous operation of both furnace and heat pump, and
prevents direct transition from heat pump to furnace operation.
When system is dual fuel (heat pump and furnace), set to ON.
When system contains fan coil, set to OF. Factory default is OF
(off).
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 10.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to alternate between OF and ON on
large display. Factory default is OF.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
OPTION 11—DUAL FUEL CROSSOVER TEMPERATURE
This option requires prior selection of heat pump (DIP switch
1—ON) and dual fuel equipment (Option 10—ON). It allows
selection of an outdoor temperature of OF, 5, 10, 15, 20, 25, 30,
35, 40, 45, 50, or 55°F. Outdoor temperature sensor must be
attached. If temperature is selected and outdoor temperature sensor
is not attached, error message E3 will appear. Heat pump is
prevented from operating for outdoor temperatures below selected
temperature. If OF is selected, outdoor temperature does not affect
system operation. Factory default is OF (off).
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 11.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to move between OF, 5, 10, 15, 20,
25, 30, 35, 40, 45, 50, or 55 on large display. Factory
default is OF.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
OPTION 12—DEFROST HEAT SELECT
This option allows installer to select the amount of heat provided
by Thermidistat Control during a heat pump defrost cycle. This can
be very helpful in maintaining a comfortable leaving air temperature during defrost. The Thermidistat Control senses when defrost
is in progress by monitoring voltage placed on the O line by the
heat pump while defrosting. It responds by turning on selected
combination of W1 and W2 during defrost. Note that this is very
different from the operation of an ordinary thermostat, which
cannot sense defrost in progress and only turns on its W outputs in
response to a temperature demand. Combinations of W1 and W2
are selected via the following:
The selection procedure is given below. If 0 is selected, operation
is like that of an ordinary thermostat, and a wire is required
between W2 of outdoor unit and a selected W on indoor unit.
When selection 1, 2, or 3 is made, no wire should be connected
from outdoor W2 because this connection may override selection
made. Obviously the heater must be in 2 sections, and fan coil
jumper must be removed between W1 and W2 for there to be a
difference between selections 1, 2, and 3. For most heaters, W1 is
lower wattage heater, and W2 is higher, although some have equal
elements for W1 and W2. Consult fan coil/heater combination for
the actual wattage connected to each of W1 and W2.
TABLE 1—W1 / W2 OUTPUTS
SELECTION DEFINITION
0
1 Only W1 is turned on.
2 Both W1 and W2 turned on.
3
Neither W1 or W2 is turned on.
This is factory default.
Only W2 turned on (available
only if 3-stage heat is selected).
In dual fuel applications, above selection choices apply and can be
used to select low or high heat if furnace is 2 stage. W1 will
produce low heat. W1 and W2 together produce high heat. This
option provides no value with single-stage furnaces because only
1 value of heat is available.
The selection choices guarantee selected outputs will be on during
defrost. If room temperature demand requires additional heat, it
will be supplied, resulting in additional outputs being turned on. If
room overheats, specified outputs will not turn off, guaranteeing a
sufficiently warm leaving air temperature during defrost. Temperature overshoot during defrost can occur, but is almost never
noticeable because of the short duration of the defrost cycle (4
minutes typical, 10 minutes maximum).
An additional feature of Thermidistat Control defrost is that it
always allows defrost cycle to run to completion. The Thermidistat
Control leaves the Y output on as long as outdoor unit holds
voltage on the O line, even if it is satisfied. This prevents
premature termination of defrost cycles, which occur with normal
thermostats.
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 12.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to move between 0, 1, 2, or 3 (if
available) on large display. See Table 1 for effect of these
choices. Factory default is 0.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
OPTION 13—ROOM TEMPERATURE OFFSET ADJUST
This option allows calibration (or deliberate miscalibration) of
room temperature sensor. There are various reasons why homeowners may want to have displayed temperature adjusted to a
higher or lower value. The selected number is number of degrees,
plus or minus, which will be added to actual temperature. The
numbers can range between -5 and +5. Factory default is 0. This
adjusted value will be used as actual temperature for both display
and control action. For example, if 2 is selected, 72°F actual will
read 74°F. If set point is 72°F, the room will control to an actual
temperature of 70°F which will be displayed and acted upon as if
it were 72°F. The effect is that a positive number selection will
make the room temperature lower and vice versa. The Thermidistat
Control is calibrated within an accuracy of plus or minus 1° when
shipped from the factory, so this adjustment will provide the best
accuracy when set to 0.
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 13.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to move between -5, -4, -3, -2, -1,
0, 1, 2, 3, 4, or 5 on large display. Factory default is 0.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
—5—
OPTION 14—HEAT/COOL DEAD BAND ADJUSTMENT
This option selects the minimum difference between heat and cool
set points. A larger difference saves energy and a smaller difference decreases temperature difference between heating and cooling. Factory default is 2, which means cooling set point must be a
minimum of 2° above heating set point. An attempt to move them
closer will result in one "pushing" the other to maintain the
required difference.
Depending on set points, moving dead band closer than 2° may
result in regular cycling between heat and cool when AUTO mode
is selected. However, this cycling cannot occur more often than 1
transition every 20 minutes. The system has a built-in requirement
that it cannot switch between heat and cool without a 20 minute
"off" time between the 2 operations. Specifically, to switch from 1
mode to the other, there must be no demand for the old mode and
a demand for the new mode, and this must exist continually for 20
minutes before transition to the new mode will occur.
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
"To enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 14.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up or down buttons to move between 0, 1, 2, 3, 4, 5, or
6 on large display. Factory default is 2.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
OPTION 15—ENABLE AUTO MODE
This option allows the installer to enable or disable AUTO mode
(automatic changeover between heat and cool). When disabled,
AUTO icon does not appear when successive presses of MODE
button are used to move between OFF, HEAT, COOL, and
EHEAT (in heat pump systems). Factory default is ON (AUTO
enabled).
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 15.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up and down buttons to move between OF and ON on
large display. Factory default is ON (AUTO enabled).
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
→
OPTION 16—RESERVED FOR FUTURE USE
→
OPTION 17—ENABLE NON-PROGRAMMABLE OPERATION
This option converts the programmable Thermidistat Control to a
non-programmable control for those users who do not want
programmability. The clock is retained, but the days of the week
and the daily schedules have been eliminated, making it operate as
if HOLD were permanently ON. Some of the buttons (used in
programming only and now not needed) are redefined to simplify
the non-programmable operation. To match these redefined buttons, a new keypad label, included with the Thermidistat, must be
placed over the original keypad label. Fig. 2 shows both the
original keypad label and the non-programmable keypad label.
When this option is selected, the new keypad label must be applied
over (or in place of) the original. Because these adhesive-backed
keypad labels are not designed to be removed, this conversion
should be considered permanent. Once the change to nonprogrammable operation is done, a procedure is not provided to
easily change it back. Should this change be needed, it is best to
trade the Thermidistat for one which has not been converted.
Both programmable and non-programmable versions of the Homeowner’s Manual are available.
Once it has been determined that a particular installation is to be
made non-programmable, the only changes required are:
• Attach non-programmable keypad label over original programmable one.
• Set Configuration Option No. 17 to ON.
To attach the provided non-programmable keypad label, carefully
peel off its backing and apply it over the original keypad label.
PLEASE HEED: Once the new keypad label makes contact, it will
stick firmly in place and adjustments cannot be made. CAREFULLY locate an edge of the keypad label, making sure its
position and orientation are correct. Then, from the attached edge,
smooth the rest of the keypad label over the original. Make sure the
new keypad label does not interfere with the motion of the buttons
which it surrounds.
TO SELECT:
1. Enter configuration mode if not already there. See Step 4
"To Enter Configuration Mode." Use up and down buttons
to make small (now flashing) display indicate 17.
2. Press SET TIME/TEMP button once to flash large display.
3. Use up and down buttons to move between OF and ON on
large display. Factory default is OF.
4. Press SET TIME/TEMP button again to flash upper small
display for selection of another option, or press END to exit
configuration mode.
→
E. Redefinition of Buttons
Fig. 2 shows the original (programmable) button labels on the left
and the redefined (non-programmable) buttons on the right. In the
figure, the buttons are numbered for easy reference. They are not
numbered on the actual product. Six of the buttons (numbers 1
through 5 and 9) have been redefined.
Button 3 originally alternated between time, cool set point, and
heat set point with each press. Now, button 1 selects the cool set
point, button 2 selects the heat set point, and button 3 selects time,
now used only to set the clock. Note that the days of the week are
gone.
Button 5 used to alternate between humidify and dehumidify. Now
button 4 selects dehumidify and button 5 selects humidify.
Button 9 now loses the HOLD label, making it END only. This
button is only used to END the humidity screen and the configuration mode.
These changes both simplify operation for the homeowner and find
use for the buttons which are no longer needed when programmability is removed.
V. SYSTEM START-UP AND CHECKOUT
The Thermidistat Control is designed with a built-in installer test
capability. It allows easy operation of equipment without delays or
set point adjustments to force heating or cooling.
To enable installer test mode, move DIP switch No. 4 to ON
position. To access this switch, open case as described in Step 2.
Use the corner of a small screwdriver to slide switch No. 4 to ON
position.
While in installer setup mode, clock will display "InSt," FAN
button will control fan, and MODE button will control heating and
cooling.
A. To Test Fan:
F,an button switches FAN icon between AUTO and ON. While
ON is displayed, G output will be on, turning fan on. Allow up to
10 sec after button is pressed for fan to turn on and off. On some
fan coils, fan continues to operate for 90 sec after G signal is
removed.
—6—
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